This invention relates to a method of polishing optical fiber connectors. More particularly, this invention relates to a polishing method as a part of a production process for connectors each with a plurality of optical fibers protruding from a front surface of a main body and a pad which is used in such a polishing process such that the variations in the length of protrusion can be reduced and the protruding optical fibers will each have a flatter front surface.
Optical fiber connectors of this type have been known, and it has also been known to polish such optical fiber connectors by using a fibrous material such as comprising nylon and polyethylene with abrasive particles attached thereto and without using a slurry. This method, however, is less than satisfactory for many reasons such that the process takes too long a time, that the finished surfaces tend to be scratched and that sufficient protrusions cannot be obtained. More significantly, such prior art methods have not been able to sufficiently control the protrusions of the individual optical fibers such that the variations among the protrusions of the individual fibers were relatively large and the tips of the protruding optical fibers were not sufficiently even, smooth or flat, tending to become thinner near the front end.
It is therefore an object of this invention to provide a new method of polishing optical fiber connectors with a plurality of optical fibers therethrough such that the optical fibers protrude from the front surface of a main body by an improved length of 1-3 microns and preferably longer with reduced variations and have flatter, smoother and more even front surfaces than was possible with prior art methods.
A method embodying this invention, with which the above and other objects can be accomplished, may be characterized as comprising the steps of carrying out a preferential etching step of the front surface by using a textile pad free of abrading particles affixed thereto and a slurry containing abrading particles of a relatively larger size and thereafter polishing front portions of the optical fibers with a polishing pad with a porous and compressive sponge-like material without abrading particles affixed thereto and a slurry of another kind containing relatively smaller abrading particles. Such a sponge-like material may comprise polyurethane and is required to have hardness within a specified range. By a method of this invention with the use of a polishing pad as described above, optical fiber connectors with a plurality of fibers can be produced with the optical fibers protruding by longer distances and more uniformly, and having smoother front surfaces.